[PATCH] D11938: [InstCombine] SSE/AVX vector shifts demanded shift amount bits

[Michael Kuperstein via llvm-commits]

mkuper accepted this revision.
mkuper added a comment.
This revision is now accepted and ready to land.

LGTM, with a nit, and a question about unrelated code. :-)


================
Comment at: lib/Transforms/InstCombine/InstCombineCalls.cpp:259
@@ -214,3 +258,3 @@
   if (CDV) {
     // SSE2/AVX2 uses all the first 64-bits of the 128-bit vector
     // operand to compute the shift amount.
----------------
Could this code also be replaced by a call to SimplifyDemandedVectorElts(), to remove duplication? Or does it do something smarter?

================
Comment at: lib/Transforms/InstCombine/InstCombineCalls.cpp:876
@@ +875,3 @@
+
+    // SSE2/AVX2 only uses all the first 64-bits of the 128-bit vector
+    // operand to compute the shift amount.
----------------
all -> only?


Repository:
  rL LLVM

http://reviews.llvm.org/D11938